Conventional magnetic disk drives are information storage devices which utilize at least one rotatable magnetic media disk with concentric data tracks, a read/write transducer for reading and writing data on the various tracks, an air bearing slider for holding the transducer adjacent to the track generally in a flying mode above the media, a suspension for resiliently holding the slider and the transducer over the data tracks, and a positioning actuator connected to the suspension for moving the transducer across the media to the desired data track and maintaining the transducer over the data track during a read or a write operation.
The recording density of a magnetic disk drive is limited by the distance between the transducer and the magnetic media. One goal of air bearing slider design is to "fly" a slider as closely as possible to a magnetic medium while avoiding physical impact with the medium. Smaller spacings, or "fly heights", are desired so that the transducer can distinguish between the magnetic fields emanating from closely spaced regions on the disk.
In addition to achieving a small average spacing between the disk and the transducer, it is also critical that a slider fly at a relatively constant height. The large variety of conditions the transducers experience during the normal operation of a disk drive can make constancy of fly height anything but a given. If the flying height is not constant, the data transfer between the transducer and the recording medium may be adversely affected.
To ensure regular fly height, both disks and sliders are often coated or finished with compositions which will lubricate the respective surfaces or provide a hardened smooth surface. Magnetic disks are usually covered with a lubricant. In turn, the air bearing surface of a slider is usually finished with a smooth, hardened coating.
For example, all of U.S. Pat. Nos. 5,159,508; 5,175,658; and 5,271,802 show a magnetic head slider with an adhesive layer and a thin amorphous hydrogenated carbon layer which are used as a protective coating. The layers are deposited on the slider by plasma assisted chemical vapor deposition.
Japanese Patent Publication 7-331440 discloses formation of a crystalline carbon thin film on the surface of a metallic magnetic film. The film is formed by plasma chemical vapor deposition.
Ganapathi et al., U.S. Pat. No. 5,336,550, shows a magnetic disk slider with an adhesive layer and a continuous coating of carbon on its air bearing surface. The carbon coating is formed by sputter deposition.
Dovek, U.S. Pat. No. 5,499,149, shows a slider with front and rear air-bearing pads, giving improved interface properties. One objective of Dovek is to modify flying height and slider design so that the slider can withstand contact with the lubricant film on the disk.
Schmidt et al., U.S. Pat. No. 5,266,409, shows alloy films in which carbon, silicon, hydrogen, and fluorine are the principle elements. The films are deposited by plasma processing, using an RF self bias chamber or an ion beam deposition system. The films can be doped with fluorine, boron, oxygen, argon or helium for magnetic medium overcoat applications. The principle gases for these films are CH.sub.4 /SiH.sub.4 and other dopant gases such as argon, helium, diborane (B.sub.2 H.sub.6) and CHF.sub.3.
Despite these advances, the varied environments that a disk drive is subjected to can create mechanical interaction between slider and disk. This mechanical interaction, often called "stiction", is a frictional resistance between slider and disk which prevents normal disk rotation and alters slider fly height. Lubricants, normally used to coat the disk to enhance operation, may also attract moisture and organic contaminants. In turn, these contaminants may increase the potential for stiction events between disk and slider.
As a result, there is a need for methods of surface modification which will provide a satisfactory conditioning of the substrate surface before definition of the slider surfaces to enhance disk drive operation.